Fire sprinkler systems have been used in the United States to protect warehouses and factories for over one hundred years. Fire sprinkler systems are positioned near the ceiling of a room where hot “ceiling jets” spread radially outward from a fire plume. When the temperature at an individual sprinkler reaches a pre-determined value, the thermally responsive element in the sprinkler activates and permits the flow of water as a water jet through an orifice toward a deflector. The metal deflector redirects the water jet into thin streams or “ligaments” that break up into droplets due to surface tension. The water droplets serve three purposes: (1) delivering water to the burning material and reducing the combustion rate, (2) wetting the surrounding material and reducing the flame spread rate, and (3) cooling the surrounding air through evaporation and displacing air with inert water vapor.
A typical sprinkler has a coverage area of 200 ft2 (18.5 m2), which is typically measured in a circular pattern with a radius of 8 feet (2.5 m) or in a square pattern with equal sides of 14 feet (4.25 m). A typical metal building includes at least three beams, such as rafters, extending along the width of a space and separated from each other by a distance of 25-30 feet (7.5 m to 9 m). As shown in FIGS. 3 and 4, a conventional fire sprinkler system for a typical metal building includes four supply lines, each with four typical sprinklers.
From a labor and materials viewpoint, the installation of every individual supply line is an additional cost. An additional supply line requires additional labor, as the installers of the fire sprinkler system must fasten each supply line to a structural member near the ceiling, which typically requires the use of a ladder or a platform. An additional supply line also requires additional metal, which is the typical material for the supply lines. Thus, there is a need in the fire suppression and extinguishment field to create an improved sprinkler system and method of installation that reduces the labor and/or materials costs. This invention provides such improved sprinkler system and method of installation.